you are able to put those declarations out of the subnet stuff, you can post them anywhere in your config file.
option domain-name "x.x";
option domain-name-servers x;
option time-servers x, x;
option netbios-name-servers x;
option netbios-node-type 8;
option lpr-servers xx;
option smtp-server see below;
option pop-server machinename/ip;
option log-servers machinename/ip;
ddns-update-style interim;
ddns-updates on;
ddns-domainname "yourname.here.com";
ddns-rev-domainname "in-addr.arpa";
update-static-leases on;
those are the GLOBAL options for your configuration, and now if you are going to work with pools / groups etc, you can specify
option routers IP.AD.DR.ESS which is quite handy of course if you have 2 gateway machines and you pool is for dhcp client machines which gets a router on your ADSL line for example and the server machines go out through the other gateway over the lease line.. pretty neat uh ?